Microelectromechanical Systems (MEMS) devices, such as MEMS sensors, are widely used in applications such as automotive, inertial guidance systems, household appliances, protection systems for a variety of devices, and many other industrial, scientific, and engineering systems. Such MEMS sensors are used to sense a physical condition such as acceleration, pressure, angular rotation, or temperature, and to provide an electrical signal representative of the sensed physical condition.
Capacitive MEMS inertial sensors, such as accelerometers, gyroscopes, and the like, typically include a movable mass that is suspended from a substrate. The movable mass moves, i.e., rotates or translates depending upon the design and sensing direction, in response to an external force. Motion of the movable mass results in a change in electrical capacitance, with respect to the sensed force, to vary the output of an energized circuit. MEMS inertial sensors are often subject to high acceleration forces, referred to herein as shock events, in off-axis directions. Unfortunately, the spring suspension designs used to suspend a movable mass may not be robust to such shock events leading to device failure.